NASA Finds Greenland Becoming More Green by the Day

Greenland may be on its way to earning its namesake far sooner than expected: recent research conducted by scientists at NASA indicates that the island nation experienced more days of melting snow in 2006 than it has on average. Daily observations taken by satellite sensors since 1988 have shown that melting days on the island have increased progressively, and that they have been taking place more and more often at higher altitudes.

"The sensors detected that snowmelt occurred more than 10 days longer than the average over certain areas of Greenland in 2006," said Marco Tedesco, the study's lead scientist and a member of the Joint Center for Earth Systems Technology and NASA's Goddard Space Flight Center in Maryland. Tedesco's "melt index," which estimates the impact of global warming on Greenland's snow by multiplying the number of melting days by the melting area, showed that Western, northeastern and southeastern coast areas in particular saw the largest number of melting days in 2006.

The major concern is that more melting could result in faster glacial flow and thus more water pouring from the ice sheets into the ocean, leading to a rise in sea levels. "The melting snow produces liquid water that will potentially influence sea levels," Tedesco said. "And some of the liquid water will drain into glaciers through cracks and vertical passages, called moulins, reaching the bedrock below and lubricating the ice sheet."In addition to this worrisome scenario, increased melting could cause less of the sun's radiation to be reflected back into the atmosphere, a direct consequence of melted and refrozen snow absorbing more sunlight than dry snow.

"Although wet and dry snow look similar at first glance, wet and re-frozen snow absorb more of the sun's radiation, reflecting only 50-60 percent back into the atmosphere. Dry snow, on the other hand, reflects about 85 percent of the sun's radiation," he said. "In other words, melting snow absorbs three to four times as much energy as dry snow, greatly affecting Earth's energy budget."

This will only continue the trend of increasing polar temperatures and will likely speed it along, magnifying the noxious effects of global warming on the entire island and surrounding areas.

"The International Polar Year's focus on this part of the world gives us an ideal opportunity to combine research results on snowmelt from satellites as well as from climate models to better understand how melting is really affecting the mass balance of Greenland's ice sheet. We need to link all of this data together to get a better view of this complex system."